1. Field of the Invention
The present invention is directed broadly to apparatus for ensuring the closure of a door and more particularly to apparatus for sealing a door.
2. Description of the Prior Art
In many applications it is desirable to have a chamber door sealingly engage a chamber. Sterilization chambers represent one such application. In a sterilization chamber, a gasket is positioned between the door and an end ring of the chamber. It is critical that the door be sealed such that the gasket contacts the sterilizer end ring with an adequate amount of pressure so that the door will not leak when the chamber is pressurized for a sterilization operation. Typically, a sterilization chamber door must be sealed to approximately thirty-five to forty pounds of force to prevent the door from leaking.
Currently, the distance between the door and the chamber end ring is used to determine if the gasket is compressed to a desired degree. Limit switches are provided which indicate when the distance between the door and the end ring is correct. At that distance, the gasket should be sufficiently compressed such that the desired amount of pressure exists between the gasket and the end ring. However, the gasket compresses with time and age such that the desired amount of pressure is not achieved by the former position of the door with respect to the end ring. The distance between the door and the end ring must be decreased to achieve the same amount of pressure between the gasket and the end ring. That necessitates repositioning the limit switches.
Thus, the need exists for an inexpensive apparatus which determines if a chamber door is properly sealed based on the amount of pressure exerted by the gasket upon the chamber end ring and not based on the position of the door with respect to the chamber end ring.